This invention relates to a cartridge locking device for an automatic gun.
An automatic gun is in general arranged to perform a series of automatic loading operations, after the gun has been fired, including extraction of an empty cartridge by a backward movement of a breech block which closes a breech face of a barrel; the return of a trigger device to a state of preparation for the next firing; then, concurrently, pushing up a cartridge removed from a magazine by an upward swaying action of a carrier; and sending the cartridge into a barrel chamber through a forward movement of the breech block. This series of actions (hereinafter will be called a rotating operation of an automatic gun) are accomplished in an extremely short period of time. After firing the gun, it is important for safety to have a timing arrangement that the next cartridge is pushed up or lifted by the carrier when the empty one has been completely ejected from a receiver by an extractor. In view of the importance of the above stated timing, heretofore the following arrangement has been employed in general: a cartridge lock normally attached to a receiver was used for locking a cartridge biased by a spring to be displaced from a magazine. The cartride was released from the lock and allowed to move onto the carrier when the breech block retracted. Then, also a cartridge locking latch was provided which locked the next cartridge and a carrier locking latch which restricted the upward sway of the carrier until the next cartridge was placed on the carrier with the breech block having been sufficiently retracted to complete the ejection of the empty cartridge.
However, such a conventional arrangement required many component parts and resulted in a complex construction. In addition to such drawbacks, it was necessary to have some means for releasing the carrier from the carrier locking latch for loading the magazine with cartridges, because the upward sway of the carrier was normally restricted. This also has been a drawback of the conventional arrangement.
In various studies conducted by the present inventor for elimination of such drawbacks of the conventional arrangement, the following points were noted:
(1) When a breech block has been retracted into a receiver, as caused by the spring force of a recoil spring located in a stock or the like, and begins to move forward to return to its initial position, the force of the forward movement of the breech block urges the carrier to sway upward. Such an upward swaying force on the carrier is exerted only by the forward movement of the breech block.
(2) Accordingly, the restriction on the upward swaying action of the carrier by a carrier lock is required only until a cartridge is removed from the magazine when the breech block urges the carrier to sway upward.
(3) As for the cartridge lock, since the barrel chamber must be loaded with the next cartridge shortly after the ejection of the emptied cartridge, the next cartridge must be released from the lock at a stage prior to such loading while the cartridge must always be kept locked with the exception of this stage.
(4) Heretofore, release of the upward sway of the carrier from the restriction has been effected by pushing the carrier latch with the bottom rim of the cartridge itself when it is moved onto the carrier.
The inventor thus has discovered that the best result can be obtained by releasing the cartridge lock either when the retraction of the breech block reaches about a maximum stroke or slightly earlier and, at the same time, by restricting the upward sway of the carrier due to the limiting force of the breech block until the cartridge is completely moved onto the carrier. This discovery has led to the present invention.